A typical flight control system utilizes control surfaces to control flight direction. In the case of a missile, fins typically provide these control surfaces. In general, movable fins attach to movable shafts which extend from the body of the missile. These fins move in various directions in response to movement of these shafts to control flight.
Manufacturers typically provide devices which lock the fins in place prior to missile launch. Such locking devices hold the fins in rigid and stable positions in order to prevent wear and tear on the drive mechanisms responsible for operating the fin shafts. For example, in the context of a missile positioned on the exterior of an aircraft, the fins of the missile are subjected to high aerodynamic loading prior to launch. Without the use of such locking devices, there is a greater likelihood that such loading will cause distortion and fatigue failures of the drive systems (e.g., motors, crank arms, drive trains, etc.) which are responsible for moving the fin shafts.
One conventional locking device includes, for each movable fin, a pin which locks into a crank arm configured to operate that fin. When the missile is launched (e.g., from an aircraft), the pins retract from the crank arms thus allowing the crank arms to move the fins. To assemble a missile with these conventional locking devices, the manufacturer typically selects and installs pins for locking the fins so that the fins reside as close as possible to their neutral (or ideal) positions for minimal friction and wear, and for high accuracy. In particular, a technician manually choose among multiple pins having different predefined offset ends, and a pin having a particular offset may work for one fin but not all fins of the same missile due to differences in tolerance stack up at each fin. In one conventional situation, the manufacturer provides the technician with a wide assortment of different pins to choose from (e.g., 10 different pins) with each pin having a slightly greater incremental offset.